Navy officers knew that Aaron Alexis had been arrested in 2004 for shooting out the tires of a car - in a blackout fueled by anger - and yet they admitted him into the Navy and granted him security clearance anyway, a senior Naval officer told CNN.

"It appears as if investigators were aware of the incident, interviewed him and were satisfied that it did not preclude granting the clearance," the officer said.

Alexis, who killed 12 people Monday at the Washington Navy Yard, was a military contractor who used a valid identification to gain access to the secured facility, law enforcement officials said Tuesday.

Bill Clinton will speak at the Democratic convention later this month.

(CNN) — Multiple sources tell CNN that former President Bill Clinton will have a speaking role at the Democratic Convention, scheduled to take place in Denver later this month.

The sources say he will speak Wednesday night, the night of the vice presidential nominee’s speech. Barack Obama will officially become the presidential nominee the next night.

Candy Crowley also reports Obama and Bill Clinton spoke today.

News of the former president's role leaked out as reports of tension between the Clinton and Obama camps over fundraising and convention planning issues, and the release of a YouTube clip showing Clinton telling supporters they should develop some sort of “strategy” to make sure their positions were represented at the Denver convention.

Obama said Thursday that the controversy over whether the New York senator's delegates would be able to vote for her at the Democratic convention was a media creation.